Ladder scaffold



- Jan. 27,- 1970' Pf'w. LE'lsT LADDER SCAFFOLD 4` Sheets-Sheet l FiledJune 20. 1968 ATTORNEY P. W. LElST LADDER SCAFFOLD v Jan. 27, 1970 4Sheets-Sheet 2 Filed June 20. 1968 INVENTOR PAUL W. LEIST Bv Z ATTORNEYJan. 27, v1970 P. w. L ElsT l LADDER scAFFoLD Filed June 20. 1968 4Sheets-Sheet 5 mit |NvENT oR PAUL WLEST ATTORNEY Jan. 27, 1970 P. w. IEls'r 3,491,852

LADDER SCAFFOLD Filed June 20. 1968 4 Sheets-Sheet 4 lNvEN'ToR PAUL w.LEIST BYZQZ ATTORNEY United States Patent O 9 Claims ABSTRACT OF THEDISCLOSURE The disclosed embodiment employs a pair of ladders havingside poles and rungs of aluminum tubing with hooks fastened to the topsof the side poles to suspend the ladders. Each ladder has a platformadjust-ably projecting from side poles on hooks engaging slots in theside poles. A plank land guard rail are suspended between the laddersand platforms. The platforms have hinged floor panels so as not toobstruct use of the ladders.

BACKGROUND OF THE INVENTION The embodiment of the present inventiondisclosed here was designed primarily for use in the constructionindustry and particularly for use by structural steel workers. Thus,unlike the typical extension ladder that is designed to lean up againstthe wall of the building, the preferred embodiment disclosed here isprovided with hooks so that it may be suspended vertically from the topof a wall, a sill, a structural member or some other such support. Theend use of such a ladder scaffold is to provide a ladder and an elevatedworking platform for one or more Working men.

For years scaffolds have been laboriously constructed frameworks ofmetal or wood beams. For years, also, pairs of ladders have been used tosupport a plank between them by :means of ladder jacks, such as areshown in U.S. Patent Nos. 1,441,847 and 1,578,388, that are hooked tothe rungs of the ladders. A variation of the same idea for use on stepladders is shown in U.S. Patent No. 1,961,863. Some special ladders havebeen suggested for specific uses, and one such arrangement uses twoladders mounted to face one another so that the scaffold of planks canbe laid directly across the rungs of the two ladders such Ias is shownin U.S. Patent No. 3,213,964. Such specialized ladders lack theversatility necessary for general applications. The conventional lad-derjack, obstructing the rungs of the ladder presents an awkward barrier toanyone trying to climb the ladder and it lacks the strength, stabilityand reliability necessary for high level Work.

SUMMARY OF THE INVENTION The present invention relates to a ladderscaffold in which the ladder is made of a pair of spaced apart verticalside poles separated by a plurality of transverse rungs that are endmounted to the side poles and a platform havingr one end releasablyfastened to the side poles to project therefrom with brace membersconnecting opposite ends of the platform to said side poles at aposition spaced from said one end of said platform.

The present invention also resides in the combination of two suchladders with said platforms mounted thereon supporting between them astage that is end mounted to adjacent side poles of the ladders and theadjacent sides of said platforms.

The combination making up the invention provides combined ladder andscaffold in which the scaffold portion is supported entirely from theside poles of the ladder so as not to obstruct the rungs of the ladder,at once making the scaffold easily and safely accessible and the ladderunobstructed and safely usable for Workmen. Also, the ladder scaffold ofthe present invention is relatively 3,491,852 Patented Jan. 27, 1970 icelight weight, is easy to use in any position and height of the scaffoldportion, and is readily adjustable. The ladder may be supported eitherfrom the top or the bottom, and its length extended. A small scaffoldmay use only one ladder, or a larger scaffold may be supported by twoladders. Of equal and perhaps even greater importance than all otherobjects and advantages of the invention is the fact that the inventionprovides a more stable, reliable and safe ladder and scaffold than hadhitherto been possible with prior art structures.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a view in perspective of the ladder scaffold embodying thepresent invention.

FIG. 2 is a side elevation of a ladder scaffold embodying the presentinvention with portions broken away to show the fastening means forconnecting the various elements together.

FIG. 3 is an elevation in section taken along the line 3 3 in FIG. 2.

FIG. 4 is a side elevation of the Vertical side poles of the ladderportion.

FIG. 5 is an elevation in section of a top end of one of the side polesof the ladder taken along the line 5 5 in FIG. 1.

FIG. 6 is a top view in section of the side poles shown in FIG. 4 takenalong the line 6 6 therein.

FIG. 7 is a side elevation of a portion of a side pole of the ladderwith portions broken away to illustrate the connection of extendingsections of a side pole.

FIG. 8 is a side elevation in section of a portion of the side pole of aladder embodying the present invention taken along the line 8 8- in FIG.1 to illustrate the fastening lof the platform brace to the side pole.

FIG. 9 is a partial side elevation with portions broken away of theladder and platform taken along the line 9 9 in FIG. 1.

FIG. 1() is an alternative embodiment showing a side elevation withportions broken away and adjustable brace for a platform.

FIG. 1l is a front elevation of a portion of a ladder scaffold showingthe back mounting of the stage onto the side poles of the two ladderstaken along the line 11 11 in FIG. 1.

FIG. 12 is a front elevation taken along the line 12-12 of FIG. 1illustrating the structure of the platform mounted on the ladder.

FIG. 13 is a sectional view of the stage taken along the line 13 13 inFIG. 1 illustrating the structure of the plank.

FIG. 14 is a partial side elevation in section of a top hook on a sidepole of a ladder embodying the present invention with clamping means tosecure the ladder to a high beam.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 a complete ladderscaffold embodying the present invention is shown, and it employs twoladders 1 and 2 mounted side by side and spaced apart, and these laddersare identical in all respects, save one, so that except for the onedifference the same reference numerals will be employed in both and onlyone need be described. Each ladder has two vertical side poles 3 and 4that are parallel to one another and spaced apart, supporting betweenthem a plurality of horizontal rungs 5 that are end mounted tothe insidesurfaces of the side poles 3 and 4 at regular spaced intervals. The sidepoles 3 and 4 are made of aluminum tubing having rectangular crosssections and hollow interiors, and each has a foot 6 or 7 pivotallymounted at the bottom end by means of a pin 8 or 9. The ladders 1 and 2differ in the shapes of the hangers 10, 11, 12 and 13 mounted on the topends of the vertical side poles 3 and 4, the ladder 1 on the left havingsimple L-shaped hangers and 11 fastened to the tops ofthe vertical sidepoles 3 and 4, respectively, and the ladder 2 on the right havinghook-shaped hangers 12 and 13 mounted on the top ends of the verticalside poles 3 and 4. The hangers 10, 11, 12 and 13 are mounted on theends of the respective vertical side poles 3 and 4 by means of a tongue14 welded or riveted inside the top end of each of said vertical sidepoles 3 and 4 to project into the interiors of the respective hangers10, 11, 12 and 13 and bolts 15 pass through the hanger tongue 14 tosecure the respective hangers 10, 11, 12 and 13 on the ends of the sidepoles 3 and 4. This stru-cture is illustrated clearly in FIG. 4, and inFIG. 7 it is shown that extension side poles 3 can be secured togetherby inserting the tongue 14 in the top of the lower side pole 3 or 4 intothe bottom end of the adjacent upper side pole 3 or 4 after removal ofthe foot 6 0r 7.

Part of the fastening means for assembling the ladder scaffold portionof the present invention is provided by slots 16 that are cut at regularintervals through the lateral outside walls of the tubes making up thevertical side poles 3 and 4. It may be noted that the lateral slots 16are formed at the level of each rung 5 with one additional lateral slot16 spaced equidistant between the rungs 5. Also, a plurality of slots 17are cut through the front walls of the vertical side poles 3 and 4 atregular intervals, in this embodiment level with the placement of therungs 5. If the ladders 1 and 2 are of the type designed to lean againsta structure rather than to hang from it, additional slots could be cutthrough the back walls of the vertical side poles 3 and 4.

Each of the ladders 1 and 2 has a platform 18 mounted on it, and sincethe platform 18 on the ladders 1 and 2 are identical only one need bedescribed with the same reference numerals being used in allillustrations of the platform 18. The platform 18 is made up o-f twohorizontal beams 19 and 20, which are hollow aluminum tubes havingrectangular cross sections, and the beams 19 and 20 are spaced apart thesame distance as the vertical side poles 3 and 4. A fastening means inthe form of a hook 21 is secured on the inside end of each of theho-rizontal beams 19 and 20 closest to the respective side poles 3 and 4of the ladders 1 and 2, and this hook 21 is so shaped so as to t insidethe front slots 17 in the side poles 3 and 4 and to engage the frontwall of the tubes that make up the vertical side poles 3 and 4. Theoutside ends of the horizontal beams 19 and 20 have upwardly projectingbrace eyes 22, and platform braces 23 and 24 have lower ends forked tofit around the brace eyes 22 and are fastened to the brace eyes 22 bybrace eye pins 25 inserted through the holes in the ends of the platformbraces 23 and 24 and through the brace eyes 22. Brace hooks 26 arefastened on upper ends of the platform braces 23 and 24 as fasteners topass through the front slots 17 two rungs above the front slots 17through which the beam hooks 21 pass and engage the walks of the tubularvertical side poles 23 and 24.

The beam hooks 21, brace hooks 26 and the brace eyes 22 are similarlyformed and mounted to their respective members, in that each is made ofaluminum sheet stock formed in the desired configuration. The hook 21 or26 is fitted snugly through the slot cut in the tubular member 19, 20,23 or 24 in which it is mounted and there it is welded or riveted intoposition so as to securely anchor it to its respective tubular members19, 20, 23 or 24. The brace eye 22 is formed from a rectangular tab 27of aluminum plate that also serves as a bracket for mounting the bottomend of the railing post 28. A D 29 is formed on the top of the railingpost 28 to receive and support a guard rail 30. A side rail 31 has oneend abutting and fastened to the railing post 28 and its opposite endfitted with a hook 32 that engages one of the lateral slots 16 and theadjacent vertical side poles 3 o-r 4 between the horizontal beams 19 and20 of the platform 18 and the top of the platform braces 23 and 24. Theside railings 31 are also pinned to the adjacent platform braces 23 and24.

Viewing the platform 18 from the front, as in FIG. l2 or from the top,as in FIG. l a panel 33 can be seen hinge mounted' to the horizontalbeam 19 by a pair of butt hinges 34 to bridge theA space between the twohorizontal beams 19 and 20. The weight of the panel 33 is sustained onchannels or angles sections 35 and 36 that are welded or riveted to thesides of the horizontal beams 19 and 20, respectively. To stabilize theplatform 18, the panel 33 is pinned to its lower position to the channelsections 36 on the horizontal beam 20` by pins 37.

FIGS. 9 and 10 illustrate `alternative means for adjusting the length ofthe platform braces 38 and 39, respectively. In the embodiment shown inFIG. 9, the platform brace 38 is made up of two telescoping sections 40and 41. The lower section 40 has its end forked by a slot 42 to receivea brace eye 43 on the end of one of the horizontal beams 19 and 20. Apin 44 secures the lower section 40 to the brace eye 43 on the end ofone of the horizontal beams 19 or 20. The lower section 40 telescopesinside the upper section 41, and the lower Section 40 has a plurality ofpeg holes 45 to receive a peg 46 which also passes through a hole (notshown) in the upper section 41 so that the length of the overallplatform brace 38 can be quite substantially varied. In FIG. 10, theplatform brace 39 is made of a single bar of aluminum with a pluralityof regularly spaced holes 47 through it. In this embodiment the platform18 has a horizontal beam 418 with a vertical slot 49 cut through itswall at the outside end to receive the platform brace 39, and it has apeg hole (not shown) cut horizontally through it and a peg 50` isinserted through the peg hole in the ends of the horizontal beam 48 andany one of the holes 47 in the platform brace 39 so as to allow thelength of the platform brace 39 to be effectively varied. Adjustablelength platform braces of which the adjustable braces 38 and 39 areexamples, are essential if the ladder scaffold is used with the ladders1 and 2 leaned against the structure with the platform 18 slung beneaththem.

A stage 51 may be suspended between the two ladders 1 and 2 and theirrespective platforms 18 to fabricate a large scaffold capable of safelyand conveniently supporting a number of workmen. The structure of thestage 51 is illustrated by the sectional view in FIG. 13 which shows twotubular aluminum girders 52 and 53 which have a plurality of smallertransverse beams 54 end mounted between the girders 52 and 53 at regularlengthwise intervals. The transverse beams 54 support two planks 55 and56 parallel to the girders 52 and 53, and extending the length of thestage 51. The top surfaces of the planks 55 and 56 are flush with thetop surfaces of the girders 52 and 53 to provide the effect of a lloorfor the workmen to stand on.

The inside girder 52 is suspended from the vertical side poles 3 and 4of the ladders 1 and 2, respectively, in the manner best illustrated inFIG. 1l. An eye projects upwardly from each end of the inside girder 52,and arms 58 and 59 are pivotally fastened to the eyes 57 by pins 60which pass through the respective arms 58 and 59 and the eyes 57. Thearms 58 and 59 are made of aluminum tubing having a rectangular crosssectional shape and both the bottoms and top ends of the arms 581 and 59have slots cut into them. The eyes 57 t loosely in the slots and thebottom ends of the arms 58 and 59 so that the arms 58 and 59 can bepivoted about the pins 60, and the hooks 60 and 61 are welded or rivetedin the slots at the tops of the arms 58 and 59. The hooks 6-2 and 61 arecut from aluminum plate and shaped to lit through the lateral slots 16in the vertical side poles 3 and 4 of the ladders 1 and 2 respectivelyat a level one rung above the desired level of the platform 51 tosupport the inside beam 52.

The outside girder 53 is supported on hooks 63- that are welded orriveted in vertical slots formed in the ends of the outside girder 53.The hooks 63 form a fastening with the slots 64 cut in the horizontalbeams 19 and 20 of the platforms 18 of the ladders 1 and 2,respectively, which support the outside girder 53 of the stage 51. Thestructure of the hooks 63 is illustrated in FIG. 12 where it can be seenthat the hooks 63, like the other hooks 62, 61, 21, 26 Yand 32 are cutfrom aluminum plate and welded or riveted in slots in the girder 53.

FIG. 14 illustrates, as an alternative to the L-shaped hangers and 11and the hook shaped hangers 12 and 13 illustrated on the ladder 1 and 2illustrated in FIG. l, a clamping hanger 65. The clamping hanger 65 ismounted on the ends of the vertical side poles 3 and 4 and it is made oftwo solid aluminum members -66 and 67, an L-shaped member 66 and anU-shaped mem'ber 67. The two members 66 and 67 have horizontal, axiallyaligned holes bored through them to receive a threaded shank 68 of acrank 69. A ange 70 is formed about the shank 68 adjacent to a handle 71of the crank 69 to bear against theoutside of the L-shaped member 66that is mounted on the vertical side poles 4 or 3. A portion of the hole72 through the U-shaped member 67 of the hanger 65 is of reduceddiameter and is threaded to engage the threaded shank 68 of the crank69. Thus by turning the crank handle 71, the U-shaped member 67 of theclamping hanger 65 can be drawn toward or moved away from the L-shapedmember 66 that is mounted on the end of the Vertical side pole 3 or 4.

An eye beam 74 is shown in section in FIG. 14 with the clamping hanger-65 clamped tightly about the top horizontal web 75 of the beam 74 toillustrate the manner in which the clamping hanger 65 may be used. Ascan be seen in the drawing, the L-shaped member 66 of the clampinghanger 65 that is mounted on the end of the vertical side poles 3 and 4has a reduced horizontal extension 75 that ts inside a cavity 76 formedin the U-shaped member 67 to lend stability to the clamping hanger 65.The vertical portion of the L-shaped member 66 also has a cavity 77formed to receive the tongue 14 projecting from the top end of thevertical side pole 3 or 4 so that the clamping hanger 65 can be securelymounted qn the top end of the vertical side pole 3 or 4 in the samemanner that the L-shaped hangers 10 and 11 and the hook shaped hangers12 and 13.

In use, atladder scaffold embodying the present invention; manifestsgreat versatility, safety, efficiency and convenience. The ladders 1 and2 may be made as long as desired by adding the necessary number ofladders, fastening them together in a manner shown in FIG. 7 anddescribed above. When the desired length of the ladders 1 and 2 havebeen assembled, the ladders 1 and 2 may be suspended in position asshown in FIG. 1 utilizing either the L-shaped hangers 10 and 11, or thehook shaped hangers 12 and 13 or the clamping hangers 55, as is mostappropriate in the particular situation. Then the platforms 18 may bemounted on the ladders 1 and 2 by fastening the horizontal beams 19 and20 to the vertical side poles 3 and 4 engaging the hooks 21 in the frontslots 17 at the desired height. Then the brace hooks 26 on the top endsof the platform braces 23 and 24 may be fastened to the -vertical sidepoles 3 and 4, respectively, by engaging the brace hooks 26 in the frontslots 17 three rungs above the level of the horizontal beams 19 and 20.For some uses, it may be that only one of the ladders 1 or 2 is needed,and in others one of the ladders 1 or 2 with a scaffold made up of theplatform 18 mounted on it will best suit the needs. Commonly, the stage51 will be suspended between the two ladders 1 and 2 and their platforms18 by fastening the arms 58 and 59 to the respective side poles 3 and 4by engaging the hooks 61` and 62 on the tops of the arms 58 and 59 intothe lateral slots 16 of the vertical side poles 3 and 4, and by engagingthe hooks 63 on the ends of the outside girder 53 into the slots 64 inthe horizontal beams 19 and 20 of the two platforms 18. The pivotallymounted arms 58 and 59 obviate the need to position the ladders 1 and 2precisely before mounting the stage 51, so that even if the ladders 1and 2 are a little too close together, or a little too far apart thehooks 61 and 62 are readily engaged into the appropriate lateralfastening slots 16 in the vertical side poles 3 and 4 and the ladders 1and 2 easily adjusted until the arms 58 and 59 hang straight. The hooks63 on the ends of the outside girder 53 of the stage 51 will fall intothe slots 64 in the horizontal beams 20 and 19 of the platforms 18 whenthe ladders 1 and 2 are adjusted so the arms 58 and 59 hang straight.The safety railing 30 is easily mounted by sliding it through the Ds 29formed in the tops of the railing posts 28. It is a significant featureof the invention that the presence of the platform 18 in no wayinterferes with the use of the ladders 1 and 2 by the workmen, becausethe oor panels 33 are hinge mounted to open as is illustrated in dottedline in FIG. 12 so that a workman can easily step through the platform18 going up or down the ladder 1 or 2, rand does not have to climbprecariously around equipment hung on the rungs 5.

The embodiment described above represents the best mode presentlycontemplated by the inventor for carrying out this invention, but theinvention itself is set forth in the claims that follow.

What is claimed is:

1. A ladder comprising the combination 0f two spaced apart vertical sidepoles arranged parallel to one another;

a plurality of rungs end mounted between said pair of vertical sidepoles at regular intervals along the length of said vertical side poles;

and a hanger fastened to the top end of each of said vertical side polesto support and suspend said ladder, each of said hangers including twoclamping members, one of said clamping members being fastened to the top0f said Ivertical side pole and' the other of said clamping membersbeing movable by a crank operated screw member toward and away from saidirst cl-amping member to tightly grasp a upporting structure betweensaid clamping memers.

2. A ladder as set forth in claim 1 wherein said vertical side poles arehollow tubular members;

and extension side poles are end mounted to said vertical side poles byconnecting means telescoping inside said vertical side poles -and saidextension side poles to be fastened to each.

3. A ladder scaffold comprising the combination of a ladder having apair of parallel spaced apart 'vertical side poles with ends adapted tosupport said ladder and a plurality of horizontal rungs end mountedbetween said vertical side poles at regular intervals along the lengthof said vertical side poles;

and a platform having a pair of horizontal parallel beams attached tosaid vertical side poles by fastening means to extend outwardlytherefrom, a horizontal oor panel supported by said beams to extendparallel to said rungs across said ladder, and brace members extendingfrom outer ends of said horizontal beams and fastened to said 4verticalside poles -at points spaced from said oor.

4. A ladder scaffold as set forth in claim 3 wherein said vertical sidepoles are hollow tubes having slots through its tube walls;

and said fastening means are hooks on the ends of said horizontal beamsadapted to engage said slots in said vertical side poles.

5. A ladder scaffold as set forth in claim 3 wherein said floor panel ishinge mounted at one side to one beam of said pair of horizontal beamsand is supported at its other side on the other beam of said pair ofhorizontal beams t0 be swung about its hinge mounting to provide accessto said ladder.

6. A ladder scaffold as set forth in claim 3 wherein a pair of saidladders with said platforms are mounted side by side in spaced apartrelationship;

and a stage is suspended between adjacent vertical side poles of saidladder and between said platform of said ladders, said stage having afloor to support workmen.

7. A ladder scaffold as set forth in claim 6 wherein said platform hashinge mounted floor panels to be swung open to allow access to saidladder.

8. A ladder scafford as set forth in claim 6 wherein said stage has armsprojecting upward from each end and pivotally end mounted to said endsof said stage, and hooks on said arms engage said yvertical side polesto suspend said stage therefrom,

and fastening means on said ends of said stage engage said platform.

9. A ladder scaffold as set forth in claim 6 wherein` a guard rail issupported 0n posts projecting vertically from said platform and said'guardrail extends parallel to the length of said stage spaced above anedge of said stage.

References Cited UNITED STATES PATENTS REINALDO P. MACHADO, PrimaryExaminer U.S. Cl. X.R.

